1. Field of the Invention
This invention relates to a means for securing the flange of a "Christmas tree" installation, valves or other equipment to cooperating flanges in pipeline headers and pipelines and more particularly, to a security locking bolt which is designed to secure such flanges and to prevent the unauthorized separation of the flanges to prevent theft of the "Christmas tree" installation or other equipment. In a preferred embodiment the security locking bolt of this invention includes a bolt body having a security bolt head integrally formed on one end thereof and provided with a hollow bore which is partially threaded to threadably receive a locking bolt for securing a locking head on the opposite end of the bolt body. The locking bolt is recessed inside the locking head and an end cap tightly covers the access opening which receives the locking bolt. In another preferred embodiment of the invention a hardened steel roller bearing is inserted in the bolt body bore between the locking bolt and the security bolt head in order to discourage removal of the security locking bolt by sawing the bolt at a point between the flanges. In yet another preferred embodiment of the invention the roller bearing and the locking bolt are each provided with an internal longitudinal aperture and a grease fitting is provided in the security bolt head in order to facilitate forcing grease through the grease fitting, into the barrel of the bolt body and through the apertures in the roller bearing and the locking bolt to remove the end cap by application of pressure.
2. Description of the Prior Art
Many attempts have been made in the prior art to develop a reliable mechanical means for locking flanges together in order to discourage the theft of "Christmas tree" equipment and other installations, such as valves, from pipelines and pipeline headers in oil and gas operations. An early "Nut Lock", is disclosed in U.S. Pat. No. 280,125, to F.C. Brauchler. The "Nut Lock" disclosed in this patent includes a primary bolt having an interior and exterior threaded leg, which exterior threads receive a primary nut provided with an extending flange member which is engagable with the head of a secondary bolt threadably secured in the threaded interior of the primary bolt and having a portion of the threaded shank extending from the head of the primary bolt to receive a secondary nut. When the secondary bolt is tightened on the secondary nut and against the flanges extending from the primary nut and the secondary nut is tightly secured against the head of the primary bolt, the nut lock is in functional configuration to secure a pair of flanges or other mechanical contrivances, as desired. U.S. Pat. No. 439,279, to J. Kramer et al, discloses a "Nut Lock", which is similar to the "Nut Lock" described in U.S. Pat. No. 280,125. In the case of the Kramer "Nut Lock", the primary bolt is threaded internally through only a portion of its length and a second bolt is inserted in the internally-threaded primary bolt shank to secure the nut in position on the primary bolt. U.S. Pat. No. 857,295, to H.H Mudge, discloses a "Bolt" having a cap covering the access drive opening thereof, which cap is fitted with cap screws having shaped heads which require a specialized tool for removal to provide access to the drive opening in the bolt. Similarly, U.S. Pat. No. 2,770,998, to R. F. Schwartz, discloses a "Tamper-Proof Screw having Frusto-Conical Head With Flat Tool Engaging Facets Thereon". The screw of this invention is characterized by a head having a particular shape which requires a specialized tool to engage the head and remove the bolt. U.S. Pat. No. 4,253,509, to James R. Collet, discloses a "Theft Deterrent Locking Nut" for securing flanges, which apparatus includes a nut-like device having a smooth outer surface which is resistant to the effects of conventional wrenches, a male threaded member having an internally-threaded axial bore adapted to threadably engage the nut-like member, a locking screw for threadably engaging the internal bore of the male member and having a head that mates with the smooth outer surface of the nut-like device and an environmental plug for insertion into the driving recess or bore of the screw to prevent foreign and corrosive matter from entering the recess. The locking screw threads are of opposite turn with respect to that of the nut-like device, so that the locking screw must first be removed before the nut may be removed. With the locking screw in place the driving recess of the nut is inaccessible, the locking screw head having conformed to the configuration of the nut to form an essentially uniform, smooth and continuous outer surface which is virtually inoperable by conventional wrenches. A "Security Method and Apparatus" is disclosed in U.S. Pat. No. 4,358,941, to John C. Zimmer, which device includes a bolt having a first hole drilled radially therein, a second threaded hole drilled axially therein to intersect the first hole and a third hole formed axially therein connecting the second hole with the end of the bolt. A bar is insertable into the first hole to extend radially outside of the bolt to prevent a nut from being removed from the bolt. The bar is secured in the bolt by means of a pickproof lock which has a screw portion threadably engagable with the second hole to engage the bar and a lock body configured to fit the third hole.
One of the problems inherent in most of the prior art locking devices for securing flanges in oilfield equipment is the susceptibility of these devices to failure due to the use of cutting torches and saws. The theft of oil and gas field valves, Christmas trees and related equipment from wellheads located in remote and unguarded areas is reaching epidemic proportions in this country and over the world. In a very short time, a thief using conventional adjustable wrenches or a cutting torch or saw equipment can unbolt or cut a wellhead Christmas tree and remove it from the wellhead casing flange. When the cost of the Christmas tree and the loss of production of oil or gas, as well as the man hours required to replace the equipment and to restore the well to the on-stream condition is considered, it will be realized that the theft of such equipment can be an extremely costly proposition.
Accordingly, it is an object of this invention to provide a new and improved security locking bolt which is designed to deter thieves and reduce the theft of oilfield valves and equipment, including Christmas tree installations and other equipment in the oilfield.
Another object of the invention is to provide a security locking bolt which is inexpensive to manufacture, easy to install and disassemble with the proper tools and extremely difficult to remove by would-be thieves without these tools.
Another object of this invention is to provide a security locking bolt for securing flanges in oilfield pipelines, headers and equipment, which can be quickly and easily assembled and disassembled using the proper tools and which cannot be disassembled when locked without the use of such tools.
Another object of this invention is to provide a new and improved security locking bolt which is characterized by a stainless steel body intergrally carrying a bolt head at one end and a removable locking head at the opposite end, which body includes an internally-threaded bore capable of receiving a recessed locking bolt to removably secure the locking head onto the bolt body in oppositely-disposed relationship with respect to the bolt head, wherein the recessed locking bolt is not accessible for removal except by use of specified tools.
A still further object of this invention is to provide a security locking bolt having a body portion, a fixed head and a removable locking head on opposite ends, which body portion includes a partially threaded bore, a hardened steel roller bearing rotatably positioned in the bore to deter cutting of the bolt body by a saw or other abrasive means and a recessed locking bolt cooperating with the locking head and the threads in the bore to removably secure the locking head on the body portion.